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Search: id:A051501
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| A051501 |
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Bertrand primes: [ 2^b ], [ 2^2^b ], [ 2^2^2^b ], ..., where b is approximately 1.2516475977905. |
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+0
2
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OFFSET
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1,1
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COMMENT
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The existence of b is a consequence of Bertrand's postulate.
a(n+1) is the smallest prime greater than 2^a(n). Hence a(5) is much larger than the largest known prime, which is only 2^32582657-1. - T. D. Noe (noe(AT)sspectra.com), Oct 18 2007
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REFERENCES
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R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Exercise 4.19.
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EXAMPLE
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[ 2^2^2^b ] = 37, so a(3) = 37.
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CROSSREFS
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Cf. A079614 (Bertrand's constant).
Adjacent sequences: A051498 A051499 A051500 this_sequence A051502 A051503 A051504
Sequence in context: A084436 A053609 A036780 this_sequence A135378 A077398 A067083
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KEYWORD
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nonn
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AUTHOR
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Jud McCranie (j.mccranie(AT)comcast.net)
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EXTENSIONS
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The next term is too large to display and in any case b is not known sufficiently accurately to compute it.
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